speech & hearing: nervous system

control system

what is the nervous system?

• _____ _____ of the body

nervous system

the most important regulator of movement including the control & coordination of the speech subsystems:

• respiration

• phonation

• articulation/resonance

regulator

the nervous system is the most important ______ of movement including the control & coordination of the speech subsystems:

central; peripheral

nervous system breakdown:

• ______ nervous system:

  • brain

  • spinal cord

• ______ nervous system:

  • somatic system:

    • cranial & spinal nerves

  • autonomic system:

    • basic bodily functions

peripheral nervous system

includes the somatic & autonomic system

somatic

peripheral nervous system:

• ______ system

  • cranial & spinal nerves

cranial and spinal nerves (somatic system)

peripheral nervous system:

• transmit & receive nerve impulses to & from all the muscles & organs of the body

autonomic system

peripheral nervous system:

• basic bodily functions

autonomic system

peripheral nervous system:

• breathing

• digestion

• heart rate

1400 g

brain tissues weighs approximately how much?

glial cells; neurons

brain tissue is made up of:

• connective tissue cells aka ______

• nerve cells aka ______

glial cells

functions:

• metabolic support (transports nutrients & removes waste)

• secretion of CSF

• response to injury

• insulation of nerve fibers

glial cells

types:

• astrocytes (most common - blood-brain barrier)

• oligodendrocytes (CNS - myelin producing)

• schwann cells (PNS - myelin producing)

• microglia (keep CNS clean - immunological)

astrocyte (star)

• connect blood capillaries & assist in transporting substances from the blood to nerve cells

• partially establishes blood-brain barrier

• forms glial scar to restrict inflammation

oligodendrocytes

______ in the CNS form layers of insulation, called myelin, that wrap around the nerve cells

schwann cells

______ in the PNS form layers of insulation, called myelin, that wrap around the nerve cells

microglia

keep the CNS clean by engulfing & destroying harmful organisms

neurons

structures that receive, process, & transmit information to, from, & within the nervous system

100

_____ billion neurons in the CNS

neurons

basic structure of _____ is the same with a few modifications depending on their specific function

soma

cell body formed by a nucleus surrounded by a mass of cytoplasm. major metabolic activity of the neuron takes place in here

dendrites

short projections that branch off of the cell body. transmit nerve impulses toward the cell body

toward

dendrites transmit nerve impulses ______ the cell body

axon

projection that transmit nerve impulses away from the cell body

away

axons transmit nerve impulses ____ from the cell body

myelin sheath; nodes of ranvier

most neurons are wrapped in _____ _____ to insulate & protect the axon with breaks known as the _____ _____ _____ to speed up the rate of nerve tranmission

synapses

tiny gap between adjacent neurons

synapse

chemical & electrical signals are able to cross the _____, allowing communication between neurons

cell body

contains cytoplasm, nucleus, organelles

dendrites

short projections that conduct impulses toward the cell body

axon

longer projection that conducts impulses away from the cell body

myelin

sheet of connective tissue wrapped around the axon, interrupted by nodes of Ranvier

terminal branches

endpoint of axon

terminal buttons

small swellings at the ends of the terminal branches

vesicles

tiny packages in the terminal buttons containing neurotransmitters

synapse

gap between neurons; can be axonal, somatic, dendritic, glandular, or muscular

axons

____ are wrapped together in bundles that form nerve pathways or tracts

sensory or motor

nerve pathways are either _____ or _____

sensory (afferent)

transmitting information from sensory receptors toward the CNS (body to brain)

motor (efferent)

transmitting information from the CNS toward muscles & glands (brain to body)

mixed

contain both sensory & motor

interneurons

involved in processing information in the brain, not transmitting it

neurons

have unique capabilities for communication within & between cells

neurons

to achieve rapid, long-distance communication, _____ have special abilities for sending electrical signals along axons

axon

cell body of a neuron communications with its own terminals via the _____

neurotransmission

communication between neurons is achieved by the process of ______

CNS and PNS

major components of the nervous system

CNS

brain & spinal cord

PNS

controls voluntary movement & sensory reception

brain, cortex, cerebrum, basal nuclei, thalamus, hypothalamus, brainstem (midbrain, pons, medulla), limbic system, cerebellum, spinal cord

schematic of CNS:

cranial nerves, somatic (afferent and efferent), autonomic (sympathetic, parasympathetic)

schematic of PNS

CNS

involved in all aspects of information processing:

• interpretation of incoming sensations

• interpretation of sensory information

• planning, organizing, & monitoring

• memory

• language

• abstract functioning

3

the CNS is protected by _____ layers of connective tissues - meninges

sensory and motor

PNS transmits _____ & _____ information to & from the CNS

PNS

serves as a relay between the brain, spinal cord, & the rest of the body

pia mater, arachnoid, and dura mater

what are the 3 layers of meninges? (bottom to top)

meninges

form a protective system of tissue & fluid around the brain & spinal cord

dura mater

_____ _____ “tough mother”

• dense protective tissue layer

arachnoid mater

______ ______:

• contains vascular supply to surface of brain

pia mater

______ _____:

• most delicate, innermost meningeal layer

subdural space

between the dura mater & arachnoid lies the _____ _____

subarachnoid space

between the arachnoid & the pia mater is the ______ ______

cerebrospinal fluid (CSF)

the subarachnoid space is filled with ______ ______

CSF

contains proteins & glucose that provide energy for cell function that help to prevent infection

dura mater

meninges layers:

• outer layer lining skull

arachnoid

meninges layers:

• contains blood vessels

subarachnoid space

meninges layers:

• filled with CSF

pia mater

meninges layers:

• covers brain

lateral; third; fourth

4 ventricles within the brain:

• two _____ ventricles

• the ____ ventricle

• the ____ ventricle

two lateral ventricles

which ventricles connect to the third ventricle by the interventricular foramen?

third and fourth ventricle

which ventricles are connected by the cerebral aqueduct?

4

how many ventricles do we have within the brain?

cortex; gray

the outermost layer of the brain is made up of _____, which is tissue formed by the cell bodies of neurons (also known as “____ matter”)

cerebrum; white

inner mass of the brain is the _____ & is made of nerve axons covered by myelin (also known as “____ matter”_

cortex

outer covering of the brain

cortex

irregular & bumpy

cortex; gyri; sulci; fissures

the _____ has numerous folds:

• raised surfaces called _____

• shallow depressions called _____

• deeper grooves called _____

these increase the surface area of the cortex without increasing the space needed to house it

hemispheres and lobes

the sulci & fissures divide the brain into _____ & _____

longitudinal cerebral fissure

the ______ ______ _______ divides the brain into 2 hemispheres

central sulcus

the _____ _____ separates the brain into anterior & posterior portion

lateral fissure

the ______ _____ delineates the superior & inferior regions of the brain

commissural, association, projection

3 main types of interconnecting pathways in the cortex

commissural fibers

link the corresponding areas in the right and left hemispheres

corpus callosum

the major commissural pathway

corpus callosum

thick band of white matter that runs parallel to the longitudinal cerebral fissure & connects the right & left hemisphere

updated

each hemisphere is constantly _____ as to the moment-by-moment functioning of the other

association fiberes

connect different cortical regions within the same hemisphere

fasciculi

long fibers are called _____

superior longitudinal fasciculus

______ ______ _____ links the four major lobes

arcuate fasciculus

connects parts of the frontal, parietal, & temporal lobes to each other

arcuate fasciculus

connects broca’s area to wernicke’s area

projection fibers

have long axons that extend to relatively distant neural structures & to the spinal cord

internal capsule; corona radiata

the _____ _____ & the _____ _____ form the primary links between the cortex & other regions of the CNS

internal capsule

forms the main pathway by which most nerve impulses are transmitted to & from the cerebral cortex

separated

the lobes of the brain are not completely _____ & their boundaries are not precise

not

each area is ____ the only brain site for a particular function

mirror images

the left & right hemisphere are not _____ _____ of each other in structure or function

frontal lobe

located anterior to the central sulcus & superior to the lateral sulcus

frontal lobe

devoted to language & speech, abstract functions including reasoning, problem solving, personality, & symbolic function

frontal lobe

primary motor area